With ice pellets blasting their faces and frigid water washing over the stern, a crew of 10 on the Madeira watched as a looming cliff along the North Shore of Lake Superior came into focus. A terrible storm had severed their 436-foot barge from the boat that was towing it, and waves tossed the Madeira like a piece of driftwood, pushing it ever closer to the shore. The crew was helpless.

¶ After slamming the rocks more than a dozen times, the barge cracked in half and started to sink. With winds howling and nothing to lose, one of the men leapt to a narrow ledge and lowered a rope to his crewmates. All except for one, they scrambled to safety as the ship filled with water and sank.

¶ They were the lucky ones. During that November 1905 storm, 29 ships loaded with cargo, many of them bound for factories on the East Coast, never made it home. It was called the worst storm of the century, and five years later on a cliff high above the wreckage of the Madeira, Split Rock Lighthouse was built to ensure that such a tragedy would never happen again.

¶ I've driven past that spot many times during my visits to the North Shore. From Hwy. 61, I could glimpse the tower peeking above the surrounding forest. This spring, 100 years after it was built, I stopped to explore what is now the nation's only lighthouse that still operates with its original mechanism.

"It has been a hard, harsh, heart-wringing period, and nothing can replace the many lives that have been sacrificed on the altar of commerce to appease the wrath of the lake."

Duluth Evening Herald, 1905

As I drove toward the lighthouse, thick stands of pine and birch broke the morning sun into shards of light and shadow. There were few visitors, a relief from summertime, when the park is normally packed. Even at the parking lot I couldn't see the lake, but I could hear it. As I walked toward the visitor center, which serves as a gateway to the lighthouse and three light keepers' houses, I could feel it, too. A cool wind blew off the lake. Only as I climbed the steps to the base of the lighthouse did a stunning Lake Superior panorama unfold.

Modern navigational devices eventually rendered the lighthouse obsolete (it stopped guiding ships in 1969), and it is now run by the Minnesota Historical Society. The 25-acre site is surrounded by the 2,200-acre Split Rock State Park -- one of the state's most popular parks for hiking and camping.

Like most visitors that morning, I walked past the visitor center and straight to the lighthouse, which is perched along the edge of a 130-foot cliff known as Split Rock. That's where I met Ed Maki, an interpreter who brings to life Split Rock's first light keeper with costumed tours.

Split Rock was a "bearing light," Maki said, intended to help ships locate their positions as they made their way through a part of the lake that narrows nearer to Duluth. It was a clear day, and I could see the faint outline of the Apostle Islands more than 25 miles away, but on foggy days, visibility can drop to zero.

By 1910, more than 25 million tons of iron ore had been shipped along the Great Lakes from the Mesabi Iron Range to factories and ports on the East Coast. Still, the North Shore was a wilderness and supplies and fuel to build the lighthouse had to be delivered by boat. Maki showed me the spot where provisions were hoisted from boats more than 100 feet below, using a lift system that was later replaced by a tramway.

"Lenze refused to work. All gummed up. It is very thick and oil freezes. We put 100 pounds more of weight on cable -- she makes good time now."

Light keeper Thompson, Nov. 16, 1921

Because the lighthouse lacked electricity, it operated like a big grandfather clock that needed regular winding every night during the shipping season. Three light keepers worked in shifts to keep the 2 1/2-ton Fresnel lens moving. It rotated around a kerosene light that was later replaced with an electric bulb. The lens, made in a factory in Paris, has 242 nested prisms that capture the light and send it across the lake in a focused beam that can be seen up to 60 miles away, some say. The light's rotation was kept at a precise speed to create beam pulses that boat captains could recognize.

Maki, dressed as light keeper Orren (Pete) Young in a two-piece black suit and hat, led the way as we climbed a circular staircase to the lighthouse's second floor. There, he bent over to wind the weights, which quietly rose as a thick cable wrapped itself around a spool. When he finished, gravity did its work, pulling the weights down and unwinding the cable as the 4-ton lens assembly above us rotated much as it would have in 1910.

We finished our tour at one of the restored light keeper's houses; it looked the way it would have when Young lived there in the 1920s. Young's children never lived on the site, but others did -- they were known to entertain themselves by taming chipmunks that lived among the rocks and watching the frequent lightning storms that raged across the lake. A lightning strike once hit the middle house, causing the telephone to dance across a desk and blue and orange flames to shoot out of the faucets. Maki reminded me that on that promontory the buildings are particularly exposed to the elements.

While the setting is spectacular, life on the cliff wasn't easy, Maki said. Harsh weather created unending lighthouse maintenance, and just as sailors risked their lives on the water, there were perils for workers, too.

"The 2 assistants left the station in row boat at 12:20 to go to Split Rock for mail and did not return. Keeper left the station at 8 a.m. to look for the assistants and found the boat about 2 miles from the light afloat bottom up about 20 rodds from shore. That shows that both men drowned."

Light keeper Thompson, Sunday, Oct. 2, 1917

Although saving lives was the lighthouse's main purpose, it didn't take long for it to become a popular tourist stop along the North Shore. The light keeper's daily log shows that only six weeks after it was lit for the first time a group of tourists from a nearby town showed up. In the 1930s, annual visitor numbers topped 100,000, and today half a million people visit the park and lighthouse each year.

As we descended from the second-floor watch room, I could see through porthole-style windows that the weather was changing. Billowy clouds left shadows on the calm surface of the lake, and I could hear the wind blowing through 100-year-old panes of glass that protect the lens above me.

And though the afternoon brought biting gusts off the lake -- barely a puff compared with what sailors endured during that 1905 storm -- there were plenty of tourists who wanted to see the lighthouse, a steady landmark for those traveling along the North Shore.